It is conventional to connect a gun sight to an associated gun for angular movement therewith in a tracking relationship. Quite often parallelogram linkages are utilized since the parallel and equal length relationship of the opposite sides of the linkage provides the required equal angular movement of the gun sight with the gun. See, for example, U.S. Pat. No. 2,390,516.
Couplings for angularly adjusting or disconnecting a gun sight from an associated gun have also been used in the past. U.S. Pat. No. 2,360,850 discloses a coupling which includes an eccentric for angularly aligning a gun sight with an associated gun whereupon a bolt of the coupling is tightened to secure the gun sight in the aligned condition with the gun. Likewise, U.S. Pat. Nos. 2,466,725; 3,263,567; and 3,424,052 disclose gun sight positioning mechanisms having manually actuated couplings for uncoupling the gun sight from the associated gun. Such uncoupling allows the gun sight to be aimed to view the terrain in a direction toward which the gun mount does not allow the gun to be aimed. Also, U.S. Pat. Nos. 2,369,806; 3,545,837; and 3,782,808 disclose gun sight positioning mechanisms having solenoid actuated couplings for connecting or disconnecting gun sights from their associated guns.
Other gun sight positioning mechanisms and the like are disclosed by U.S. Pat. Nos. 3,309,962; 3,355,987; 3,493,296; and 3,868,169.
Usually the field of vision of a gun sight includes a reticle having a verticle line and vertically spaced dots or cross hairs spaced along the vertical line. Aiming of the gun is accomplished by first aligning the vertical line of the reticle with the target and then moving the sight and the gun to an inclined position that will give the required projectile distance to the target. Initially the distance may have to be estimated and a round fired to determine whether the inclination corresponds to the required projectile length. For relatively short target distances, the cross lines or dots of the reticle can be aligned with the target and the impact can be viewed through the sight field of vision to determine whether a greater or lesser projectile length is necessary. However, for longer target distances, the gun and sight must be inclined at an angle that is great enough so that the target is located below the area encompassed by the sight field of vision. In such instances, the gunner must view the impact without the aid of the sight in order to determine whether the proper projectile distance to the target is present and adjust accordingly. Of course, both the sight and the gun could be moved downwardly so that the impact could be viewed through the sight but the angularly adjusted position of the gun would then have to be reset upon upward movement after the impact is viewed.